Tokyo (CNN) -- A 6.4-magnitude earthquake struck Sunday morning off the east coast of Honshu, Japan, the U.S. Geological Survey said.

The earthquake was centered 27 miles (43.5 kilometers) beneath the surface about 114 miles (184 kilometers) northeast of Tokyo, the agency said.

There were no immediate reports of injuries or damage.

The country's Nuclear and Industrial Safety Agency said there were no reports of problems at the Fukushima Daiichi nuclear plant as a result of the earthquake, according to Japanese broadcaster NHK. The plant was crippled by a much more powerful earthquake on March 11.

Japan has been struck by hundreds of aftershocks off the coast of Honshu since that quake.